title: Peripheral blood sCD3⁻ CD4⁺ T cells: a useful diagnostic tool in angioimmunoblastic T cell lymphoma.
abstract: Angioimmunoblastic T cell lymphoma (AITL) belongs to the subgroup of mature T cell lymphomas according to the World Health Organization and is one of the common T cell lymphomas in Western countries. Particularly in cases in which histological confirmation cannot be easily achieved, immunophenotyping of peripheral blood can give important information for the differential diagnosis of AITL. sCD3⁻ CD4⁺ T cells are a typical feature of AILT in flow cytometry of peripheral blood. In this retrospective study, the diagnostic value of flow cytometry for the diagnosis 'AITL' was assessed by comparing the frequency of sCD3⁻ CD4⁺ T cells in leukemic AITL patients and in patients with other leukemic CD4⁺ T cell lymphomas. Immunophenotyping of peripheral blood by flow cytometry was performed in a lymphocyte gate using fluorochrome-labelled antibodies against CD3, CD2, CD4, CD5, CD7, CD8, CD10, CD14, CD16, CD19, CD56, CD57 and T cell receptor. In 17/17 leukemic AITL patients, a small but distinct population of sCD3⁻ CD4⁺ T cells was detected (mean percentage of sCD3⁻ CD4⁺ T cells in the lymphocyte gate: 11.9 ± 15.4%, range 0.1-51.8%). In contrast, sCD3⁻ CD4⁺ T cells were found in only 1/40 patients with other leukemic CD4⁺ T cell lymphomas (one patient with mycosis fungoides). sCD3⁻ CD4⁺ T cells have a high positive predictive value (94%) for the diagnosis 'AITL'. Flow cytometry is particularly useful in the differential diagnosis of AITL, even if the aberrant T cell population has a very low frequency. Further biological characterization of this subfraction of lymphoma cells is warranted.
authors.affiliation: Department of Hematology, Oncology and Tumor Immunology, Charité-University Medicine Berlin, Campus Virchow-Klinikum, Berlin, Germany; Labor Berlin Charité Vivantes GmbH, Berlin, Germany.
authors.forename: Anju
authors.initials: A
authors.lastname: Singh
authors.forename: Richard
authors.initials: R
authors.lastname: Schabath
authors.forename: Richard
authors.initials: R
authors.lastname: Ratei
authors.forename: Andrea
authors.initials: A
authors.lastname: Stroux
authors.forename: Claus-Detlev
authors.initials: CD
authors.lastname: Klemke
authors.forename: Thomas
authors.initials: T
authors.lastname: Nebe
authors.forename: Anne
authors.initials: A
authors.lastname: Flörcken
authors.forename: Antje
authors.initials: A
authors.lastname: van Lessen
authors.forename: Ioannis
authors.initials: I
authors.lastname: Anagnostopoulos
authors.forename: Bernd
authors.initials: B
authors.lastname: Dörken
authors.forename: Wolf-Dieter
authors.initials: WD
authors.lastname: Ludwig
authors.forename: Antonio
authors.initials: A
authors.lastname: Pezzutto
authors.forename: Jörg
authors.initials: J
authors.lastname: Westermann
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood; D000951:Antigens, Neoplasm / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D017252:CD3 Complex / Q000097:blood*; D015704:CD4 Antigens / Q000097:blood*; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D018655:Lymphocyte Count; D016399:Lymphoma, T-Cell / Q000097:blood / Q000175:diagnosis; D016411:Lymphoma, T-Cell, Peripheral / Q000097:blood* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000737:chemistry / Q000473:pathology*; D011948:Receptors, Antigen, T-Cell / Q000097:blood; D012751:Sezary Syndrome / Q000097:blood / Q000175:diagnosis; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D017252:CD3 Complex; D015704:CD4 Antigens; D011948:Receptors, Antigen, T-Cell
keywords: AITL; T-NHL; angioimmunoblastic T cell lymphoma; sCD3− CD4+ T cell